fs: port vfs{g,u}id helpers to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

1 files changed, 2 insertions, 7 deletions

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 2d182aa31364..795984333bcb 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -2513,7 +2513,6 @@ int smb2_open(struct ksmbd_work *work)
 	struct ksmbd_file *fp = NULL;
 	struct file *filp = NULL;
 	struct mnt_idmap *idmap = NULL;
-	struct user_namespace *user_ns = NULL;
 	struct kstat stat;
 	struct create_context *context;
 	struct lease_ctx_info *lc = NULL;
@@ -2767,7 +2766,6 @@ int smb2_open(struct ksmbd_work *work)
 	} else {
 		file_present = true;
 		idmap = mnt_idmap(path.mnt);
-		user_ns = mnt_idmap_owner(idmap);
 	}
 	if (stream_name) {
 		if (req->CreateOptions & FILE_DIRECTORY_FILE_LE) {
@@ -2867,7 +2865,6 @@ int smb2_open(struct ksmbd_work *work)
 
 		created = true;
 		idmap = mnt_idmap(path.mnt);
-		user_ns = mnt_idmap_owner(idmap);
 		if (ea_buf) {
 			if (le32_to_cpu(ea_buf->ccontext.DataLength) <
 			    sizeof(struct smb2_ea_info)) {
@@ -2999,7 +2996,7 @@ int smb2_open(struct ksmbd_work *work)
 					if (!pntsd)
 						goto err_out;
 
-					rc = build_sec_desc(user_ns,
+					rc = build_sec_desc(idmap,
 							    pntsd, NULL, 0,
 							    OWNER_SECINFO |
 							    GROUP_SECINFO |
@@ -5128,7 +5125,6 @@ static int smb2_get_info_sec(struct ksmbd_work *work,
 {
 	struct ksmbd_file *fp;
 	struct mnt_idmap *idmap;
-	struct user_namespace *user_ns;
 	struct smb_ntsd *pntsd = (struct smb_ntsd *)rsp->Buffer, *ppntsd = NULL;
 	struct smb_fattr fattr = {{0}};
 	struct inode *inode;
@@ -5176,7 +5172,6 @@ static int smb2_get_info_sec(struct ksmbd_work *work,
 		return -ENOENT;
 
 	idmap = file_mnt_idmap(fp->filp);
-	user_ns = mnt_idmap_owner(idmap);
 	inode = file_inode(fp->filp);
 	ksmbd_acls_fattr(&fattr, idmap, inode);
 
@@ -5188,7 +5183,7 @@ static int smb2_get_info_sec(struct ksmbd_work *work,
 
 	/* Check if sd buffer size exceeds response buffer size */
 	if (smb2_resp_buf_len(work, 8) > ppntsd_size)
-		rc = build_sec_desc(user_ns, pntsd, ppntsd, ppntsd_size,
+		rc = build_sec_desc(idmap, pntsd, ppntsd, ppntsd_size,
 				    addition_info, &secdesclen, &fattr);
 	posix_acl_release(fattr.cf_acls);
 	posix_acl_release(fattr.cf_dacls);